1. FIELD OF THE INVENTION
This invention is in the field of Dentistry study appliances and study methods for correcting irregularities in the position and alignment of teeth in the mouth of the patient and also deals with the combination of such appliances with mounting apparatus for mounting an artificial model of the teeth simulating those of the patient in order to study the occulsion and the articulation of the model and to reproducably monitor the orthodontic treatment.
2. DESCRIPTION OF THE PRIOR ART
1. Prior Apparatus
Williams, U.S. Pat. No. 1,485,657, granted Mar. 4, 1924 discloses a dental articulator in which upper and lower model supporting members are relatively adjustable to obtain, in the practice of prosthesis, the proper position of the teeth on one model in the occlusal plane relative to the other model. Comparison may be made with the one model, the upper has been moved, after those in the other model have been arranged according to given measurements and calculations, thus the Williams device can serve for movement of the lower teeth to give measurements and calculations after the movement has been accomplished. Alternatively, the Williams device may be used to plan movement in order to reach the desired positioning of teeth in the upper and lower set.
The purpose of the Williams dental articulator is to provide certain movements and adjustments of the cooperating upper and lower tooth model parts which greatly facilitate its use in positioning these uppers and lowers before treatment is started or to monitor while it is going on or after it is finished. Because the position of the teeth in the x and y planes can be accurately controlled and charted with the Williams device, the use of this device will promote the accuracy of the dental work in which it is employed.
It is, however, ackward to use the Williams geared articulator with stone models based upon impressions of the teeth and a very high degree of skill is required for the Orthodontist to painstakingly chart the movements in the x and y plane for the present intermediate and desired tooth positions in each of the upper and lower sets.
In my U.S. Pat. No. 3,787,979, an Orthodontic Study device is provided wherein the position of each tooth may be universally adjusted. The tooth, in for form of a crown, is connected by a ball and socket joint to one end of a post which is secured at its other end to a supporting base plate. The post is in the form of elongated telescopic members whereby the height thereof may be adjusted. The post is secured to the base plate by a ball and socket joint whereby its position may be adjusted.
My Orthodontic Study device will serve to provide a precise replica of each tooth in each set, upper and lower, of the patient and will also serve to monitor positions of each tooth in intermediate and finished stages of orthodontic treatment. However, the mechanism for locating and moving the assemblies of upper and lower models in the x, y and z directions is required in order to provide the full scale utilization of my three dimensional study device in my aforesaid patent.
Wollney et al, U.S. Pat. No. 3,646,680, granted Mar. 7, 1972, presents an Orthodontic Force Model for demonstrating the direction of tooth displacement in response to externally applied forces. The Wollney apparatus is a system of springs which maintain a tooth model suspended in space. Forces are applied to this model and the direction in which the tooth is displaced as well as the amount of displacement are recorded and measured.
These forces based upon springs in Wollney can be estimated from positions in my own Orthodontic Study Model if there were available a mechanism to achieve x and y movements as in Williams, U.S. Pat. No. 1,485,657, but there would still be the requirement to achieve a tilting movement in the z direction (vertical) absent in the Williams construction.
The panoramic tripod head of the Leitz Company, known as the Tiltall Tripod and that of Peterson, U.S. Pat. No. 2,461,175, granted Feb. 8, 1949, are swiveling mechanisms which provide the free rotations and tilting movements required for panning in photography.
If the Williams articulator in U.S. Pat. No. 1,485,657 were to be combined with my prior U.S. Pat. No. 3,787,979, one would have an adjusting mechanism for bringing the lower and upper dental arch into position in respect to the x, y and z axes, but one would not have the ability to adjust the angle of tilt required by the jaw bone structure so that one would make calculations and measurements for planning treatment and for establishing the diagnosis without having the unique tilt of the jaw structure and the positioning of the teeth relative to the jaw bone structure as the factor which will permit achieving the desired bite.
Accordingly, the requirement for a proper and true understanding of the geometry of each of the teeth goes beyond the combination of my prior study model with the aforesaid Williams patent, particularly since the jaw structure is tilted and the relationships of the teeth and the upper and lower dental arches must be defined in precise relation to the existing jaw structure, the bite, the head structure, etc., all of these determined by X-ray. The deficiencies of a simple mounting of my three-dimensional of Stereodont Model of my aforesaid patent in the Williams articulator will be overcome by utilizing a triad of my new bit registration guide and complete coronal assemblies, this triad mount in my new geared articulator is characterized by a swiveling mechanism for free tilting movement in an entirely new relationship which permits extremely accurate measurement and charting as good as or better than the most accurate micrometric measurements using an accurate measuring microscope.